"One gram has 500 million molds, there are too many bacteria, drinking Pu'er tea is equivalent to drinking dirty water!"
Tea is a very famous "drink", has a strong health value, so it is very popular in China, some tea lovers not only have excellent tea brewing skills, but also have a lot of research on the efficacy and composition of tea.
But in recent years, there has been a saying that some teas have a lot of fungi and may even cause cancer. In 2010, seventy samples were collected in a laboratory in Guangzhou, all of which detected aflatoxin, and even some exceeded the standard, and three other mycomycins were detected.
As soon as this matter broke out, it received the attention of the masses, and even circulated a saying: Pu'er carcinogenic, will there really be carcinogens in cooked tea?
1 g pu-erh ripe tea 500 million bacteria? Drinking Pu'er equals drinking dirty water? Can Pu'er tea be drunk in the end? Let's talk about it today.
Pu'er is a moldy tea
What we call Pu'er tea usually refers to cooked tea, cooked tea and raw tea in the production engineering is still different, raw tea is one less process step than cooked tea, that is, humidification Wodui, in terms of what we can understand is fermentation.
The basic principle of humidification and fermentation is similar. All are using microbial fermentation technology to decompose organic macromolecules in food, so that they are hydrolyzed into small amino acid molecules that are more digestible and taste better.
So in the fermentation process of tea, what microorganisms are at play? What is the difference between the distribution and number of bacteria and fungi? Will these microorganisms cause harm to the human body? These are all questions worth exploring.
According to the analysis of the survey results, in the study of cooked tea, it was found that there are bacteria and fungi distributed in cooked tea, and the fungi are mainly yeast and mold.
It is worth noting that all fermented products in daily life, such as yogurt and soy sauce, contain these three microorganisms. When we think of fermented products, we generally think that only yeast is at work, and we always ignore the presence of mold.
People's impression of mold is the existence of mold that makes steamed bread moldy, makes various foods deteriorate and grow green hairs, we always think that mold is poisonous, and there is an instinctive disgust for it. But in fact, not all molds are toxic, and in the process of fermentation, some changes in type and function will inevitably occur.
After watering Pu'er and starting fermentation, the warm and humid aspergillus niger will grow rapidly in such an environment.
On the one hand, Aspergillus niger produces more than 20 kinds of hydrolases in the metabolic process, which can decompose large molecules such as proteins, sugars, fats into small molecules that are easy to digest, thereby stimulating some components in the tea leaves and making the taste of the tea better.
In addition, Aspergillus niger can also produce a lot of monosaccharides, providing sufficient nutrients for the subsequent production of other bacterial fungi.
Will there be Aspergillus aflex in Pu'er tea?
Aspergillus niger has a great effect on the improvement of tea efficacy, but Aspergillus aflex is a very strong carcinogen, so in the case of Pu'er tea with Aspergillus niger, whether it contains Aspergillus aflex has also become a major research.
Aspergillus aflex is very common in nature, but it does not exist in the fermentation process of Pu'er tea, because it and Aspergillus niger cannot coexist, and Aspergillus niger inhibits the growth of Aspergillus aflex, that is, in the fermentation process, the more Aspergillus niger, the less Aspergillus aflex.
In addition, in addition to inhibiting growth, it will also inhibit the vitality of its enzymes; the caffeine, tannins and other components contained in tea will also inhibit the growth of Aspergillus aflatogenes.
As the tea leaves are stored and dried, the moisture in the tea leaves gradually decreases, and in the middle and late stages, Aspergillus niger no longer functions and will become less and less, while the yeast on the contrary begins to play a leading role, competing with Aspergillus aflashus for nutrients and space, and continuing to inhibit their growth until Aspergillus aflatogenes completely disappears.
So many fungi in Pu'er tea are affecting the growth of Aspergillus aflex, so will some Of the aspergillus aflex still survive? The answer is no.
Scientists have conducted many experiments, bought many kinds of Pu'er tea from the market at different prices, analyzed and compared the ingredients inside, and did not find the presence of Aspergillus aflex in it. Corresponding tests have also been carried out in Europe, Japan and other regions, further verifying this conclusion.
A professor in Taiwan has carried out in-depth experiments on this, he introduced Aspergillus flavus species in normal fermented tea, cultured, and found that Aspergillus aflex can not survive normally, which shows that Aspergillus aflex can not grow in cooked tea.
Once the tea leaves are fermented abnormally and produce aspergillus flavus species, at this time the tea leaves will emit a strange taste, and normal people can easily smell it, so in the normal tea drinking process, as long as the taste color is normal, you can safely quote.
Where does Aspergillus aflatogenes come from?
Aspergillus aflatogenes is present in nature, such as walnuts, peanuts and many spoiled and moldy foods, can be found in Aspergillus aflatoxin, under certain conditions, aspergillus aflatoxin in the metabolic process will produce aflatoxin this substance.
The presence of aflatoxin does not necessarily have aflatoxin, requiring appropriate temperature, PH and humidity, the growth temperature of Aspergillus aflatoxin is 33-38 degrees, the PH value is 5; and the aflatoxin temperature is between 24-28 degrees, the humidity should reach 80%, and the yield will be high.
In the process of Pu'er fermentation, the temperature has reached more than forty degrees, and it is impossible for Aspergillus aflatogenes to survive at this time.
If some odor is smelled in the tea and aflatoxin is detected, according to experts, the reason for this may be contamination during transportation and storage.
In a sampling test in 2010, the presence of Aspergillus aflex was found, because Pu'er tea was stored in a wet warehouse, and Pu'er tea and other substances in the warehouse were cross-infected, resulting in the survival of Aspergillus aflex, which shows that the transportation and storage of tea is extremely important.
Foam in Pu-erh tea
Good tea brewing craftsmanship can make the tea drunk mellow and fragrant, endlessly evocative, in today's rapid production process, Pu'er tea outbreak problems are more and more, of which Pu'er tea foam problem is particularly serious.
One is that the tea brewing craft affects the taste and color of the tea, there is foam can try to change their own way of brewing tea, the use of the right way to brew tea will play the greatest value of Pu'er.
The other is that the counterfeiting is serious, in some areas, there is no very strict testing system, resulting in serious adulteration of tea leaves, many of these tea leaves are detritus, and even after brewing tea will produce a pungent odor, but also easy to moldy deterioration, so many people are not interested in drinking Pu'er tea.
In fact, it is very normal for there to be bacteria in tea, after all, in the process of fermentation and other processes, these bacteria play a role, not all bacteria are harmful, we do not need to worry too much. Scientists have proved that there are no toxic substances in Pu'er tea, and there is no case of drinking dirty water, so we can drink with confidence.